1. Field of the Invention
The present invention relates to a device for selectively locking and releasing a rope member extending therethrough. In the present specification the term "rope member" or "rope" should be interpreted in a broad sense so as to comprise any elongate, flexible, rope-like member, such as threads, wires, cords, lines, etc.
2. Description of the Prior Art
Locking devices of the above type may, for example, be used in sailing ships and at other locations where there is a need for quick locking and releasing of a tensioned rope or wire. As an example, the locking device of the above type may be used in connection with winches, tackles, or other pulling or falling mechanisms which may, for example, be used for hauling sails.
In a known locking device of the above type, a tensioned rope member may be passed through a passage defined between a first rope engaging surface formed on a frame member of the device, and an oppositely arranged, second rope engaging surface formed on a rope clamping eccentric which may moved manually between a rope locking and a rope releasing surface by means of a handle formed thereon. The frame member of the known locking device has a U-shaped cross-section and receives the swingably mounted clamping eccentric therein. When the eccentric is in its rope releasing position, the handle extending from the eccentric may also be received in the U-shaped frame member so that it is positioned substantially within the contour of the frame member. However, in the rope clamping position of the eccentric, the handle extends from the contour of the frame member so that the operator may grip the handle and forcibly move the eccentric into its rope clamping and locking position. In this rope clamping position, the angular position of the handle may vary depending on the thickness of the rope being clamped and on the manual force applied to the handle. Because the handle extends from the contour of the frame member in the rope clamping position of the eccentric, there is a substantial risk that the handle is accidentally moved to the rope releasing position, for example when the locking device is mounted on the deck of a sailing ship, or at other positions, where persons are moving around.
Danish Patent Application No. 4353/79 discloses a locking device of a similar type, wherein the clamping eccentric and the operating handle therefor are independently swingable elements, and the operating handle is used only for moving the swingable clamping eccentric into engagement with the rope. When a pulling force is applied to the rope the frictional forces between the rope and the rope engagement surface of the eccentric tend to move the eccentric into a more close engagement with the rope. It has been found, however, that the known locking device of the latter type is not sufficiently efficient to reliably lock a rope transmitting heavy pulling forces, for example of the order of 500 kp or more.